Socioeconomic and cultural factors associated with pap smear screening among French women living in Réunion Island.

BACKGROUND: Réunion Island is a French overseas territory located in the southern Indian Ocean, with a challenging socioeconomic and multicultural context. Compared to mainland France, Réunion has an overincidence and overmortality of cervical cancer. In order to investigate these two issues, it is important to evaluate the barriers and potential levers to Pap smear screening among female inhabitants of the island. We aimed to identify the specific socio-demographic factors, cultural factors, and living conditions associated with Pap smear screening in Réunion, with a view to increasing uptake. METHODS: We conducted a Knowledge Attitude Behavior and Practices (KABP) survey on cervical cancer screening practices among women aged between 25 and 65 years old living in Réunion Island, selected using random digit dialing sampling. Data were collected using Computer Assistant Telephone Interviews. Weighted chi-squared tests and Student's t-tests were used to compare women who had up-to-date Pap smear screening with women who did not. Weighted logistic models were used to identify the factors associated with not having up-to-date screening. RESULTS: A total of 1000 women were included in the study. Of these, 88.1% had a Pap smear test during the previous three years. Factors independently associated with not being up to date were as follows: aged over 55 (AOR 2.3 [1.2-4.3]), no children (AOR 2.5 [1.4-4.3]), having free universal health coverage (AOR 1.7 [1.1-2.7]), an income per unit consumption lower than 1500€ per month (AOR 2.0 [1.1-3.7]), low health literacy (AOR 2.7 [1.7-4.1]), not consulting a general practitioner in the prior 12 months (AOR 3.6 [2.0-6.5]), and a BMI > 30 (AOR 2.6 [1.5-4.4]). CONCLUSIONS: This is the first large-scale survey focusing on recommended Pap smear screening uptake in Réunion Island. Although self-reported screening incidence was higher than in mainland France, national screening policies must take into account the island's diverse social and cultural characteristics (e.g., an ageing population, low health literacy), while implementing actions to fight against poverty and increase general access to healthcare.

Severe leptospirosis in tropical and non-tropical areas: A comparison of two french, multicentre, retrospective cohorts.

BACKGROUND: Leptospirosis is an anthropozoonosis that occurs worldwide but is more common in tropical regions. Severe forms may require intensive care unit (ICU) admission. Whether the clinical patterns and outcomes differ between tropical and non-tropical regions with similar healthcare systems is unclear. Our objective here was to address this issue by comparing two cohorts of ICU patients with leptospirosis managed in mainland France and in the overseas French department of Réunion, respectively. METHODOLOGY/PRINCIPAL FINDINGS: We compared two retrospective cohorts of patients admitted to intensive care for severe leptospirosis, one from Reunion Island in the Indian Ocean (tropical climate) and the other from metropolitan France (temperate climate). Chi-square and Student's t tests were used for comparisons. After grouping the two cohorts, we also performed multiple correspondence analysis and hierarchical clustering to search for distinct clinical phenotypes. The Réunion and Metropolitan France cohorts comprised 128 and 160 patients respectively. Compared with the Réunion cohort, the metropolitan cohort had a higher mean age (42.5±14.1 vs. 51.4±16.5 years, p<0.001). Severity scores, length of stay and mortality did not differ between the two cohorts. Three phenotypes were identified: hepato-renal leptospirosis (54.5%) characterized by significant hepatic, renal and coagulation failure, with a mortality of 8.3%; moderately severe leptospirosis (38.5%) with less severe organ failure and the lowest mortality rate (1.8%); and very severe leptospirosis (7%) manifested by neurological, respiratory and cardiovascular failure, with a mortality of 30%. CONCLUSIONS/SIGNIFICANCE: The outcomes of severe leptospirosis requiring ICU admission did not differ between tropical and temperate regions with similar healthcare access, practices, and resources, despite some differences in patient characteristics. The identification of three different clinical phenotypes may assist in the early diagnosis and management of severe leptospirosis.

Diagnostic performance of the WHO definition of probable dengue within the first 5 days of symptoms on Reunion Island.

The relevance of the World Health Organization (WHO) criteria for defining probable dengue had not yet been evaluated in the context of dengue endemicity on Reunion Island. The objective of this retrospective diagnostic study was to evaluate the diagnostic performance of the 2009 WHO definition of probable dengue and to propose an improvement thereof. From the medical database, we retrieved the data of subjects admitted to the emergency department of the University Hospital of Reunion Island in 2019 with suspected dengue fever (DF) within a maximum of 5 days post symptom onset, and whose diagnosis was confirmed by a Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). The intrinsic characteristics of probable dengue definitions were reported in terms of sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-), using RT-PCR as the gold standard. Of the 1,181 subjects who exhibited a positive RT-PCR, 652 (55%) were classified as probable dengue. The WHO definition of probable dengue yielded a sensitivity of 64% (95%CI 60-67%), a specificity of 57% (95%CI 52-61%), a LR+ of 1.49 (95%CI 1.33-1.67), and a LR- of 0.63 (95%CI 0.56-0.72). The sensitivity and LR- for diagnosing and ruling out probable dengue could be improved by the addition of lymphopenia on admission (74% [95%CI: 71-78%] and 0.54 [95%CI: 0.46-0.63] respectively), at the cost of slight reductions of specificity and LR+ (48% [95%CI: 44-53%] and 1.42 [95%CI: 1.29-1.57], respectively). In the absence of, or when rapid diagnostic testing is unreliable, the use of the improved 2009 WHO definition of probable dengue could facilitate the identification of subjects who require further RT-PCR testing, which should encourage the development of patient management, while also optimizing the count and quarantine of cases, and guiding disease control.

Past volcanic activity predisposes an endemic threatened seabird to negative anthropogenic impacts.

Humans are regularly cited as the main driver of current biodiversity extinction, but the impact of historic volcanic activity is often overlooked. Pre-human evidence of wildlife abundance and diversity are essential for disentangling anthropogenic impacts from natural events. Réunion Island, with its intense and well-documented volcanic activity, endemic biodiversity, long history of isolation and recent human colonization, provides an opportunity to disentangle these processes. We track past demographic changes of a critically endangered seabird, the Mascarene petrel Pseudobulweria aterrima, using genome-wide SNPs. Coalescent modeling suggested that a large ancestral population underwent a substantial population decline in two distinct phases, ca. 125,000 and 37,000 years ago, coinciding with periods of major eruptions of Piton des Neiges. Subsequently, the ancestral population was fragmented into the two known colonies, ca. 1500 years ago, following eruptions of Piton de la Fournaise. In the last century, both colonies declined significantly due to anthropogenic activities, and although the species was initially considered extinct, it was rediscovered in the 1970s. Our findings suggest that the current conservation status of wildlife on volcanic islands should be firstly assessed as a legacy of historic volcanic activity, and thereafter by the increasing anthropogenic impacts, which may ultimately drive species towards extinction.

Comparing the Performance of Three Models Incorporating Weather Data to Forecast Dengue Epidemics in Reunion Island, 2018-2019.

We developed mathematical models to analyze a large dengue virus (DENV) epidemic in Reunion Island in 2018-2019. Our models captured major drivers of uncertainty including the complex relationship between climate and DENV transmission, temperature trends, and underreporting. Early assessment correctly concluded that persistence of DENV transmission during the austral winter 2018 was likely and that the second epidemic wave would be larger than the first one. From November 2018, the detection probability was estimated at 10%-20% and, for this range of values, our projections were found to be remarkably accurate. Overall, we estimated that 8% and 18% of the population were infected during the first and second wave, respectively. Out of the 3 models considered, the best-fitting one was calibrated to laboratory entomological data, and accounted for temperature but not precipitation. This study showcases the contribution of modeling to strengthen risk assessments and planning of national and local authorities.

Chlorophyllum molybdites poisoning on Reunion Island.

In France, mushroom picking is part of the culture. The practice is not without risk, as around 1300 people are poisoned each year by eating wild mushrooms on the French mainland. However, this practice is not part of local culture on Reunion Island, a French territory located in the Indian Ocean. Indeed, there are practically no reports of mushroom poisoning on Reunion Island. Here we describe, through a retrospective study, cases of mushroom poisoning recorded in the Indian Ocean toxicosurveillance system database from 2020 to 2021. Overall, 19 people were poisoned following wild mushroom ingestion on Reunion Island: 15 in 2020 and 4 in 2021. Six events were recorded: the majority of poisonings involved clusters (n = 5) during a shared meal (pan-fried), only one case was single mushroom poisoning by ingesting a raw mushroom. Of all patients, 15 cases presented a gastrointestinal irritant syndrome (latency between 30 min and 3 h). Chlorophyllum molybdites was positively identified by mycologists in 4 cases, suspected by emergency doctor in 1 case and in one self-declared case, Volvariella volvacea was consumed. Poisoning following ingestion of wild mushrooms does occur on Reunion Island, and Chlorophyllum molybdites is the main culprit.

Microplastics in the insular marine environment of the Southwest Indian Ocean carry a microbiome including antimicrobial resistant (AMR) bacteria: A case study from Reunion Island.

The increasing threats to ecosystems and humans from marine plastic pollution require a comprehensive assessment. We present a plastisphere case study from Reunion Island, a remote oceanic island located in the Southwest Indian Ocean, polluted by plastics. We characterized the plastic pollution on the island's coastal waters, described the associated microbiome, explored viable bacterial flora and the presence of antimicrobial resistant (AMR) bacteria. Reunion Island faces plastic pollution with up to 10,000 items/km2 in coastal water. These plastics host microbiomes dominated by Proteobacteria (80 %), including dominant genera such as Psychrobacter, Photobacterium, Pseudoalteromonas and Vibrio. Culturable microbiomes reach 107 CFU/g of microplastics, with dominance of Exiguobacterium and Pseudomonas. Plastics also carry AMR bacteria including ß-lactam resistance. Thus, Southwest Indian Ocean islands are facing serious plastic pollution. This pollution requires vigilant monitoring as it harbors a plastisphere including AMR, that threatens pristine ecosystems and potentially human health through the marine food chain.

Demographic responses of oceanic island birds to local and regional ecological disruptions revealed by whole-genome sequencing.

Disentangling the effects of ecological disruptions operating at different spatial and temporal scales in shaping past species' demography is particularly important in the current context of rapid environmental changes driven by both local and regional factors. We argue that volcanic oceanic islands provide useful settings to study the influence of past ecological disruptions operating at local and regional scales on population demographic histories. We investigate potential drivers of past population dynamics for three closely related species of passerine birds from two volcanic oceanic islands, Reunion and Mauritius (Mascarene archipelago), with distinct volcanic history. Using ABC and PSMC inferences from complete genomes, we reconstructed the demographic history of the Reunion Grey White-eye (Zosterops borbonicus (Pennant, 1781)), the Reunion Olive White-eye (Z. olivaceus (Linnaeus, 1766)) and the Mauritius Grey White-eye (Z. mauritianus (Gmelin, 1789)) and searched for possible causes underlying similarities or differences between species living on the same or different islands. Both demographic inferences strongly support ancient and long-term expansions in all species. They also reveal different trajectories between species inhabiting different islands, but consistent demographic trajectories in species or populations from the same island. Species from Reunion appear to have experienced synchronous reductions in population size during the Last Glacial Maximum, a trend not seen in the Mauritian species. Overall, this study suggests that local events may have played a role in shaping population trajectories of these island species. It also highlights the potential of our conceptual framework to disentangle the effects of local and regional drivers on past species' demography and long-term population processes.

Experiences of adolescents using sexual health services on Reunion Island: protocol for a qualitative phenomenological study.

INTRODUCTION: Adolescence and early adulthood are often critical periods of sexual development. The discovery of sexual intercourse can lead to sexual risk-taking which may impact the incidence of sexually transmitted infections (STIs) and unwanted pregnancies. Despite available sexual health services on Reunion Island, sexual health indicators for adolescents are very poor showing a high number of teenage pregnancies and abortions, low use of contraception and an upsurge of STIs. In contrast, this French region is equipped with many services and resources that enable young adults to make informed sexual health choices. This study protocol describes the methodology to describe adolescent experiences of using sexual health services on Reunion Island. METHODS AND ANALYSIS: A monocentric descriptive qualitative study using a phenomenological approach will be conducted from December 2022 to August 2023 and will be based on face-to-face semistructured interviews with participants aged 15-19 years and residing on Reunion Island. Recruitment will be distributed at various educational institutions and sexual health centres and will be facilitated by the 'snowball' and 'word-of-mouth' effect. Data analysis will be independently carried out by three investigators to increase reliability. An interpretative phenomenological analysis will be performed. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Ethics Committee of the Hospital Center University De Bordeaux (CER-BDX-2022-55). Data generated do not fall within the field of biological or medical knowledge nor into the category of Research Involving the Human Person as defined in Articles L. 1121-1 and R. 1121-1 of the Public Health Code in France. All participants will receive information about the study in verbal and written forms and will give their oral consent before enrolment. Results will be published in a peer-reviewed journal as well as presented and disseminated at the Regional Health Agency of Reunion Island, conferences and in meetings with school directors.

Psychometric properties of a Creole version of Medical Outcome Study - Short Form 36 among type II diabetes patients on Reunion Island.

Introduction: Health quality of life assessment is particularly important to measure the impact of chronic diseases. The aims of this study were to provide a cross-culturally adapted Creole-translation of the Medical Outcome Study Short-Form 36 (SF-36) and to assess psychometric performance of the Creole and French versions of the SF-36 among patients with type II diabetes in Reunion Island. Materials and methods: The Creole translation and cross-cultural adaptation processes were based on the International Quality Of Life Assessment (IQOLA) methods. Internal consistency, test-retest reliability, convergent and discriminant validity using Multi-Trait-Multi-Method analysis and structural validity using exploratory factor analysis of the SF-36 for both versions were performed. Results: In the Creole version of the SF-36, Cronbach's alpha exceeded 0.70 for all subscales except general health. In the French SF-36, Cronbach's alpha exceeded 0.70 on all subscales except general health and bodily pain. In the Creole SF-36, intraclass correlation coefficient (ICC) for reproducibility was suboptimal. Multi-trait multi-method analysis showed that item-scale correlation exceeded 0.4 for all items except two general health items of the Creole SF-36 and one of the French SF-36. Factor analysis of 2 versions showed that the physical functioning, vitality, and mental health were each divided into two subscales. Discussion: Overall, our findings provided evidence that the SF-36 is adapted to Reunion Island in both Creole and French versions. However, further research could be conducted to investigate French-Creole differences in perceived health status and a cultural adaptation of the French version will be considered.

Impact of the COVID-19 pandemic on severe non-SARS-CoV-2 community-acquired pneumonia in Reunion Island: a multicenter retrospective observational study, 2016-2021.

The Coronavirus 2019 (COVID-19) pandemic has had a considerable impact on the incidence of severe community-acquired pneumonia (CAP) worldwide. The aim of this study was to assess the early impact of the COVID-19 pandemic in the Reunion Island. This multicenter retrospective observational study was conducted from 2016 to 2021 in the hospitals of Reunion Island. The incidence of severe non-SARS-CoV-2 CAP, microorganisms, characteristics and outcomes of patients hospitalized in intensive care unit were compared between the pre-COVID-19 period (January 1, 2016 to February 29, 2020) and the early COVID-19 period (March 1, 2020 to October 31, 2021). Over the study period, 389 patients developed severe non-SARS-CoV-2 CAP. The incidence of severe non-SARS-CoV-2 CAP significantly decreased between the two periods (9.16 vs. 4.13 cases per 100,000 person-years). The influenza virus was isolated in 43.5% patients with severe non-SARS-CoV-2 CAP in the pre-COVID-19 period and in none of the 60 patients in the early COVID-19 period (P < 0.0001). The only virus that did not decrease was rhinovirus. Streptococcus pneumoniae was the most frequently isolated bacterial microorganism, with no significant difference between the two periods. In Reunion Island, the COVID-19 pandemic led to a significant decrease in the incidence of influenza, which likely explains the observed decrease in the incidence of severe non-SARS-CoV-2 CAP. The pandemic had no impact on the incidence of other viral and bacterial severe non-SARS-CoV-2 CAP. Monitoring influenza incidence is crucial now that COVID-19 control measures have been removed.

Ophthalmic complications during the dengue epidemic in Reunion Island in 2020: a case series and review of the literature.

INTRODUCTION: Dengue is an arboviral disease transmitted by the dengue virus, whose vectors are Aedes aegypti and Aedes albopictus. The acute phase with its cohort of well-known symptoms is usually spontaneously favorable. Since 2020 in Reunion Island, a new symptom has appeared: the ocular damage of dengue fever, which has already been described in South Asia and South-East Asia. We therefore decided to describe the clinical, biological, ophthalmological, therapeutic, and outcomes of patients with ocular manifestations during dengue fever in Reunion Island in 2020. PATIENTS AND METHODS: This was a retrospective observational study. Patients were included from January 2020 to August 2020 and then reassessed by teleconsultation 1 year later. The patients were identified from the French public health surveillance network by all ophthalmologists on the island. Medical data were collected directly from medical records. RESULTS: Twenty-eight patients were included. The mean age was 41.9 years. Ocular involvement occurred approximately 9.2 days after the onset of dengue symptoms. The main symptoms were scotoma (71.4%) and sudden decrease of visual acuity (39.2%). Eighteen patients (64.2%) had macular involvement. Fourteen patients were treated with oral or intravenous corticosteroids. Twenty-two (78.5%) patients were evaluated by telephone one year later. Scotoma and decreased visual acuity persisted in 15 patients. Thirteen patients (59%) were bothered by night driving, 32% of patients had reading difficulties and 27% of patients became sensitive to prolonged exposure to screens. CONCLUSION: Ocular complications of dengue require early and collegial management to limit the risk of long-term sequelae. Further studies on the characteristics and complications of dengue fever are needed to better understand this disease.

Emerging Corynebacterium diphtheriae Species Complex Infections, Réunion Island, France, 2015-2020.

Clinical, epidemiologic, and microbiologic analyses revealed emergence of 26 cases of Corynebacterium diphtheriae species complex infections on Réunion Island, France, during 2015-2020. Isolates were genetically diverse, indicating circulation and local transmission of several diphtheria sublineages. Clinicians should remain aware of the risk for diphtheria and improve diagnostic methods and patient management.

A rare report of H-partially deficient, non-secretor phenotype from India. An Ah like the rèunion and unlike a Para Bombay-Clarifying misinterpretations.

BACKGROUND: H-deficient phenotypes are classified as H-deficient non- secretors (Bombay Oh), H-deficient secretors (Para Bombay), and H-partially deficient non-secretors (O h reunion, Ah and Bh, ABh). REPORT: We report the first case of H-partially deficient non-secretor- the Ah phenotype from India. What makes this report interesting is that they do not fit into the Bombay, or the Para Bombay series of H-deficient phenotypes and these partially deficient non-secretors were exclusively found on Réunion Island, off the East Coast of Africa in 1982. These reunion type phenotypes have not been reported since then and may lead to misinterpretations and confusions when encountered in the current existing laboratory settings especially in the low income (LIC's) and low middle income (LMIC's) countries like our own. Moreover, literature from LMIC and LIC incorrectly uses Ah/Bh for parabombay phenotypes. CONCLUSIONS: H-deficient phenotypes are rare, challenging to identify and assign correct notations. Hence, we have highlighted characteristic differences between H-deficient phenotypes and illustrated a diagnostic laboratory approach to correctly identify and assign notations to them especially in the resource constrained settings.

From dengue outbreaks to endemicity: Reunion Island, France, 2018 to 2021.

BackgroundAfter 40 years of limited viral circulation, Reunion Island has since 2018 experienced recurrent dengue outbreaks of increasing intensity and severity.AimWe aimed to report on the epidemiology and characteristics of dengue in Reunion Island between 2018 and 2021.MethodsBetween 2018 and August 2021, we systematically collected data on dengue cases via an automated transmission system between the health authorities and the medical laboratories. We set up additional surveillance systems for dengue-related activity in primary care, in emergency departments and in inpatient departments.ResultsUntil 2020, despite numerous cases, outbreaks had a limited public health impact because of few severe cases, low lethality and no heavy burden for the health care system. In 2021, however, the number of severe cases increased (from 0.4% of all cases in 2018 to 0.8% in 2021), as did the number of paediatric cases (from 8% in 2018 to 15% in 2021) and atypical clinical forms of dengue (108 cases of post-dengue maculopathy). Of note, haemorrhagic forms were rare and multi-organ failure was the most frequent severity throughout the study period. In parallel, the dominant serotype switched from DENV2 to DENV1 in 2020 and DENV1 became the only serotype detected in 2021.ConclusionThese findings indicate that dengue is becoming endemic in Reunion Island. Since comorbidities associated with severity of dengue are common in the population, health authorities should carefully consider the impact of dengue when addressing public health policies.

Metals in the Réunion harrier: tissue concentrations and meaning for conservation.

The Réunion harrier is an endemic raptor on Réunion Island. Several threats endanger its population, poisoning by rodenticides being considered as the main one currently. No information is available on its exposure to other chemicals notably trace metal elements such as lead (Pb), mercury (Hg), and cadmium (Cd). The Réunion harrier is still a victim of poaching nowadays. When shooting is not lethal, animals may carry embedded shot in their body and thus be exposed to toxic level of Pb as demonstrated for other raptors. Moreover, recent monitoring suggests a decrease of its breeding success over time. It is known that Hg and Cd could impair reproduction and disturb embryo development in birds. The aim is to measure metal concentrations in the tissues of 30 carcasses of harrier collected from 2016 to 2021. Lead was analyzed in the liver and humerus, while Hg and Cd were measured in livers. Concentrations were compared to toxicological reference values. Overall, the Réunion harrier was not exposed to toxic levels of Pb or Cd. For Hg, 53% of the individuals have residues higher than the threshold compatible with oxidative stress, and 13% have liver concentrations above those compatible with reproduction impairment. A positive correlation was found between the proportion of urban habitat in a 55 km2 area centered on the location where the harrier was found and the concentration of Hg in the liver. We conclude that Hg exposure could be a threat for the Réunion harrier population and recommend monitoring the exposure of the most sensitive stages, i.e., embryos and nestlings, to this metal with non-invasive methods.

Dengue clinical features and harbingers of severity in the diabetic patient: A retrospective cohort study on Reunion island, 2019.

AIM: Diabetes mellitus is associated with both the risks of severe dengue and dengue-related deaths, however the factors characterizing dengue in the diabetic patient are ill-recognized. The objective of this hospital-based cohort study was to identify the factors characterizing dengue and those able to early identify dengue severity in the diabetic patient. METHODS: We retrospectively analysed demographic, clinical and biological parameters at admission in the cohort of patients who consulted at the university hospital between January and June 2019 with confirmed dengue. Bivariate and multivariate analyses were conducted. RESULTS: Of 936 patients, 184 patients (20%) were diabetic. One hundred and eighty-eight patients (20%) developed severe dengue according to the WHO 2009 definition. Diabetic patients were older and had more comorbidities than non-diabetics. In an age-adjusted logistic regression model, loss of appetite, altered mental status, high neutrophil to platelet ratios (>14.7), low haematocrit (≤ 38%), upper-range serum creatinine (>100 µmol/l) and high urea to creatinine ratio (>50) were indicative of dengue in the diabetic patient. A modified Poisson regression model identified four key independent harbingers of severe dengue in the diabetic patient: presence of diabetes complications, non-severe bleeding, altered mental status and cough. Among diabetes complications, diabetic retinopathy and neuropathy, but not diabetic nephropathy nor diabetic foot, were associated with severe dengue. CONCLUSION: At hospital first presentation, dengue in the diabetic patient is characterized by deteriorations in appetite, mental and renal functioning, while severe dengue can be early identified by presence of diabetes complications, dengue-related non-severe haemorrhages, cough, and dengue-related encephalopathy.

Evaluation of a school-based sun safety education program in Reunion Island, 2016-2017.

BACKGROUND: Sun exposure, especially during childhood, is the main environmental risk factor for skin cancers. This study evaluated the impact of the school-based sun safety education program "Living with the Sun" on the knowledge and behavior of primary school children regarding sun safety in Reunion Island. METHODS: This multicenter, comparative intervention study was conducted in selected primary schools of Reunion during the 2016-2017 school year. The intervention consisted of an in-class slide-show presentation on sun safety, a teaching guide, and school trips during which children were offered sunscreen and were requested to wear sunglasses, a T-shirt, and a cap. The children completed a questionnaire before and after the intervention. The percentage of children wearing a cap in school playgrounds at the end of the school year was compared between paired intervention and control schools. RESULTS: Seven hundred children from 7 Reunionese schools completed the questionnaire before and after the intervention. There was a statistically significant improvement in children's knowledge of sun safety, with differences between schools, teachers, school levels, and questionnaire responses. The percentage of children wearing a cap at the end of the school year was significantly higher in intervention schools compared to control schools. CONCLUSIONS: Children's knowledge and behavior regarding sun safety improved significantly as a result of the intervention.

Genetic characterization of dengue virus serotype 1 circulating in Reunion Island, 2019-2021, and the Seychelles, 2015-2016.

BACKGROUND: An unprecedent increase in the number of cases and deaths reported from dengue virus (DENV) infection has occurred in the southwestern Indian ocean in recent years. From 2017 to mid-2021 more than 70,000 confirmed dengue cases were reported in Reunion Island, and 1967 cases were recorded in the Seychelles from 2015 to 2016. Both these outbreaks displayed similar trends, with the initial circulation of DENV-2 which was replaced by DENV-1. Here, we aim to determine the origin of the DENV-1 epidemic strains and to explore their genetic characteristics along the uninterrupted circulation, particularly in Reunion. METHODS: Nucleic acids were extracted from blood samples collected from dengue positive patients; DENV-1 was identified by RT-qPCR. Positive samples were used to infect VERO cells. Genome sequences were obtained from either blood samples or infected-cell supernatants through a combination of both Illumina or MinION technologies. RESULTS: Phylogenetic analyses of partial or whole genome sequences revealed that all DENV-1 sequences from Reunion formed a monophyletic cluster that belonged to genotype I and were closely related to one isolate from Sri Lanka (OL752439.1, 2020). Sequences from the Seychelles belonged to the same major phylogenetic branch of genotype V, but fell into two paraphyletic clusters, with greatest similarity for one cluster to 2016-2017 isolate from Bangladesh, Singapore and China, and for the other cluster to ancestral isolates from Singapore, dating back to 2012. Compared to publicly available DENV-1 genotype I sequences, fifteen non-synonymous mutations were identified in the Reunion strains, including one in the capsid and the others in nonstructural proteins (NS) (three in NS1, two in NS2B, one in NS3, one in NS4B, and seven in NS5). CONCLUSION: In contrast to what was seen in previous outbreaks, recent DENV-1 outbreaks in Reunion and the Seychelles were caused by distinct genotypes, all likely originating from Asia where dengue is (hyper)endemic in many countries. Epidemic DENV-1 strains from Reunion harbored specific non-synonymous mutations whose biological significance needs to be further investigated.